The effects of iron on the cell cycle of HeLa cells

H. O. Jauregui, C. Dyer, H. Hawkins

Research output: Contribution to journalArticle

Abstract

Previous studies have shown that when nonsynchronous HeLa cells in the logarithmic growth phase are incubated in an iron rich medium, the rate of cell multiplication decreases after 24 hours of iron incubation. The present experiments were designed to determine the phase of the cell cycle in which iron exerts its negative effect on cell growth. Randomized populations of HeLa cells growing on slides were incubated with ferrous ammonium sulfate at final concentrations of 0.0035 and 0.00175 g/ml. Cell cycle analysis was accomplished using light microscopic autoradiography by counting mitoses labeled with radioactive thymidine (3H thy) in cells incubated in iron from 0 to 36 hours. In a second group of experiments, control and iron incubated cells were labeled with 3H thy, and the percent labeled nuclei was recorded hourly after 0 to 7 hours. A third group of cells was incubated with iron from 0 to 7 hours following pulse labeling with 3H thy. These were fixed at hourly intervals after a second pulse label, and the percent labeled nuclei was counted. By selective detachment of metaphase cells, a synchronous population of HeLa cells in the G1 period was obtained. These cells were also incubated with ferrous ammonium sulfate at the above indicated concentrations and fixed after pulse labeling with 3H thy. The results suggest that iron affects the cell cycle of HeLa cells by lengthening it by 4 to 5 hours. The negative effect of iron seems to be a block in the late G1 period, about 2 to 4 hours before the initiation of DNA synthesis. The possibility of a second block in the G2 phase cannot be ruled out.

Original languageEnglish (US)
JournalAmerican Journal of Pathology
Volume82
Issue number2
StatePublished - 1976
Externally publishedYes

Fingerprint

HeLa Cells
Cell Cycle
Iron
G2 Phase
Metaphase
Growth
Autoradiography
Mitosis
Thymidine
Population
Cell Proliferation
Light
Control Groups
DNA

ASJC Scopus subject areas

  • Pathology and Forensic Medicine

Cite this

Jauregui, H. O., Dyer, C., & Hawkins, H. (1976). The effects of iron on the cell cycle of HeLa cells. American Journal of Pathology, 82(2).

The effects of iron on the cell cycle of HeLa cells. / Jauregui, H. O.; Dyer, C.; Hawkins, H.

In: American Journal of Pathology, Vol. 82, No. 2, 1976.

Research output: Contribution to journalArticle

Jauregui, HO, Dyer, C & Hawkins, H 1976, 'The effects of iron on the cell cycle of HeLa cells', American Journal of Pathology, vol. 82, no. 2.
Jauregui, H. O. ; Dyer, C. ; Hawkins, H. / The effects of iron on the cell cycle of HeLa cells. In: American Journal of Pathology. 1976 ; Vol. 82, No. 2.
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